Hello Tikko!
I actually read your post (unlike some of this advice) so I'll try to help with your question. The first way is the easy way. It is to find some people who you find fun to watch on youtube and watch their stuff. You'll see who they play as and who they are playing against and get a concept of the champions and what they do.
And Fun being the important part. If you pick people who you enjoy watching, you'll keep doing it and get more into league and the entertaining players will be more accessible to you because they will be talking naturally about things and won't have cue card of topics that they are trying to get through.
The second way is also a reason why I recommended youtube. Here is the League wiki. You can just pause the video and look up the champion the player is playing and an enemy or ally champion if you have questions about them. It will also help because of the unfortunate circumstance that Riot doesn't offer all the information about champions in game or on their website.
Third way is to look up Champion Introductions. Not guides, things that say to "buy IE when such-and-such" but things that talk about the champion and what they do. Here is one that I enjoyed when I was new and helped get me into LoL. Why Buy series is a series where Kley talks about the champions in this way. He is quite good at explaining them and he tells things like not just what the abilities do but what the significance of that is. Some things have changed (like Baron), yes, but they are still valid; Champion abilities don't change entirely. I encourage you to give them a shot; this Varus one is good and maybe even more appropriate with this current meta.
